# CVE-2026-32814: libheif: Uninitialized Heap Memory Information Leak via Failed Grid Tiles

> Crafted HEIF/AVIF files leak uninitialized heap memory as pixel data, potentially exposing sensitive information in image processing applications.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 19 May 2026
- **Updated:** 20 May 2026
- **Also known as:** BELL-CVE-2026-32814, DEBIAN-CVE-2026-32814, ECHO-75d9-35e8-0f25, GHSA-4m8r-34pg-rvwc, ROOT-OS-DEBIAN-11-CVE-2026-32814, ROOT-OS-DEBIAN-12-CVE-2026-32814, UBUNTU-CVE-2026-32814

## What is CVE-2026-32814?

CVE-2026-32814 is a medium-severity vulnerability in strukturag libheif, published on 19 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and prior, when decoding a HEIF grid image with strict_decoding=false (the default), a corrupted tile silently fails to decode and the library returns heif_error_Ok with no indication of failure, leading to an uninitialized heap memory information leak. The canvas is allocated via create_clone_image_at_new_size() → plane.alloc() → new (std::nothrow) uint8_t[allocation_size] which does not zero the memory; only the alpha plane is explicitly initialized via fill_plane(), so the Y, Cb, and Cr planes contain whatever was previously at that heap address. The failed tile's region of the canvas is never written. It retains uninitialized heap data that is delivered to the caller as decoded pixel values (4,096 bytes per Y/Cb/Cr plane = 12,288+ bytes total). Any application using libheif to decode grid-based HEIF/AVIF files with default settings is vulnerable: a crafted .heic or .avif file causes 4,096+ bytes of heap memory to appear as pixel values in the decoded image, and the calling application receives heif_error_Ok, so it has no indication the output contains heap garbage. In server-side image processing, an uploaded crafted HEIF decoded and re-encoded (e.g., as PNG/JPEG for thumbnails, CDN, social media) can leak cross-user data such as auth tokens, database results, and other users' image data. This issue has been fixed in version 1.22.0.

Weakness: CWE-908 (Use of Uninitialized Resource), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-32814?


## How do I fix CVE-2026-32814?

Upgrade to a fixed version.

## Is CVE-2026-32814 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32814 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32814 and fix it if it is affected.

What it is: CVE-2026-32814 is a medium-severity vulnerability in strukturag libheif, published on 19 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32814 exists.

Affected product: strukturag libheif. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-32814/ (Markdown: https://insights.sbomify.com/CVE-2026-32814/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32814
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32814
- OSV: https://osv.dev/vulnerability/CVE-2026-32814

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-32814/
Summaries are generated and may contain mistakes; the official description above is the record.